In the lubrication and other industries, preset meters for dispensing a preset amount of fluid are desirable for a number of reasons. First of all, such meters insure that only the exact amount of a fluid is dispensed in an application, for instance exactly four quarts of engine oil are dispensed into an automobile engine. Secondly, use of the preset meter allows the operator to work on other items while the fluid is dispensing thereby enhancing productivity.
Such preset meters in general have been known and used for many years and for a long time were strictly mechanical. More recently, electronic meters come into vogue. It is desired to have a meter which is accurate yet which provides long battery life so that the unit does not need to be serviced too often.
It is therefore an object of the invention to provide a preset meter which provides long battery life and yet which is capable of dispensing amounts of fluid accurately and furthermore which is easily operated in a variety of modes by the person utilizing the device.
The meter is provided with a dispensing valve having a stem which is slightly biased to the off position. Pressing down the stem opens the valve and allows fluid to dispense while removal of pressure on the stem again allows the valve to close. A trigger which is at least as wide as two fingers is mounted on the valve stem and allowed to pivot in the range of about 5xc2x0 between a latch position where it can be engaged by a latch and a manual position where the latch does not engage it.
A latching type solenoid is operated responsive to the electronic fluid meter and the shaft is normally held in position by a magnet, the filed is which is overcome when the coil of the solenoid is energized. The meter may be of any conventional type which outputs a short electrical pulse to the solenoid which in turn operates a lever arm mounted on the shaft and a catch which can engage one end of the trigger. In normal use, the solenoid is non-energized and normally the catch member is located in a first position capable of engaging the trigger. Only for the brief period of time, when signaled by the meter that the predetermined amount has been reached, is the solenoid activated to free the catch member from the trigger.
Pulling on the trigger allows manual dispensing and rocking it in one direction allows the trigger first end to engage the catch member and rocking in the other end prevents latching so that the dispense operation may be a pure manual spring loaded operation.
These and other objects and advantages of the invention will appear more fully from the following description made in conjunction with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views.